The main reason to use it was the `rel` attribute for previous/next
pages not being indexed correctly by certain search engines when using a
relative URL. However, AFAIK that only applied to `<link>` tags, not to
`<a>` tags, and only if a `<base>` tag was defined.
In any case, it looks like the same search engines don't use the `rel`
attribute for previous/next to index pages anymore.
The `type: :feature` is automatically detected by RSpec because these
tests are inside the `spec/features` folder. Using `feature` re-adds a
`type: :feature` to these files, which will result in a conflict when we
upgrade to Rails 5.1's system tests.
Because of this change, we also need to change `background` to `before`
or else these tests will fail.
